Abstract: A dynamic focus electron gun includes a triode for initially forming electron beams and a main lens for focusing and accelerating the electron beams with dynamic electric fields, wherein the main lens includes an auxiliary electrode including three cylindrical members, each including an electric field introducing window aperture for introducing electric fields into the members and an oblong tubular electrode commonly surrounding the members and covering the electric field introducing windows. According to the present invention, interference between the electron beams can be avoided, and the focus of the electron beams can be optimized.

Abstract: An electron gun for use in a color picture tube includes electrodes forming at least one unipotential focusing lens for focusing electron beams. An electrode disposed between first and second electrodes forming a unipotential focusing lens includes first and second plate-shaped members. The first member forms, in cooperation with the first electrode, a focusing lens having an electrostatic field weaker in the vertical direction than in the lateral direction. The second member forms, in cooperation with the second electrode, a focusing lens having an electrostatic field weaker in the vertical direction than in the lateral direction. The electron gun removes halos appearing in the peripheral region of the tube screen.